Linked Life Data

8798481

Source:http://linkedlifedata.com/resource/pubmed/id/8798481

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
38
pubmed:dateCreated
1996-11-19
pubmed:abstractText
We have here investigated the effect of the regulatory Tat protein of the human immunodeficiency virus type 1 (HIV-1) on the PI 3-kinase catalytic activity in PC12 rat pheochromocytoma cells. After as early as 1 min from the beginning of the treatment with recombinant HIV-1 Tat protein, a significant increase in the tyrosine phosphorylation levels of the p85 regulatory subunit of PI 3-kinase was noticed in 48 h serum-starved PC12 cells. Moreover, the addition of Tat to PC12 cells induced a great increase in PI 3-kinase immunoprecipitated with an anti-phosphotyrosine antibody with a peak of activity (19-fold increase with respect to the basal levels) after a 15-min treatment. This increase in PI 3-kinase activity was significantly higher in PC12 cell cultures supplemented with Tat protein than in cultures stimulated by 100 ng/ml nerve growth factor (NGF; 8-fold increase with respect to the basal levels). Further experiments showed that Tat protein was able to specifically activate PI 3-kinase at picomolar concentrations. In fact: (i) maximal activation of PI 3-kinase was observed at concentrations as low as 1 ng/ml and was specifically blocked by anti-Tat neutralizing antibody; (ii) a Tat-dependent activation was also observed in experiments in which PI 3-kinase activity was evaluated in either anti-Tyr(P) or anti-p85 immunoprecipitates; (iii) 100 nM wortmannin completely blocked the Tat-mediated increase in PI 3-kinase activity both in vitro and in vivo. Our data strongly support the concept that extracellular Tat acts as a cell stimulator, inducing intracellular signal transduction in uninfected cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
22961-4
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Extracellular human immunodeficiency virus type-1 Tat protein activates phosphatidylinositol 3-kinase in PC12 neuronal cells.
pubmed:affiliation
Institute of Human Anatomy, University of Ferrara, 44100 Ferrara, Italy.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't